Abstract: A binocular is provided with a pair of telescopic optical systems. Each of the pair of telescopic optical systems has an objective lens system, an erecting optical system, and an observing optical system. The erecting optical system of each of the telescopic optical systems may be a type I or type II Porro prism, which is divided into two sub prisms respectively have two reflection surfaces. First and second hand vibration compensation mechanism is provided: (a) between the objective lenses and erecting optical systems; and (b) between the first sub prisms and the second sub prisms.

Abstract: Disclosed is an observation optical system such as a binocular. A telescopic optical system of the observation optical system is provided with a plurality of optical elements, which are arranged such that the observation optical system has a first optical axis horizontally extending and a second optical axis vertically extending when the binocular is held horizontally by a user. The observation optical system is further provided with first and second compensation optical systems that are movable to shift optical paths of light passed through the first and second compensation optical systems to compensate trembling of image due to hand vibration applied to the observation optical system. The compensation optical systems are constituted and arranged such that movement thereof will not be affected by the gravity.

Abstract: A binocular is provided with a pair of telescopic optical systems. Each of the pair of telescopic optical systems has an objective lens, an erecting system, a compensation lens and an observing optical system. The erecting system of each of the telescopic optical systems is divided into two sub prisms, a vertically extending optical axis is defined therebetween. The compensation lens is located between the first and second sub prisms such that it is movable in a horizontal plane by a driving mechanism. As the compensation lens moves, an optical path of light passed therethrough changes. Accordingly, by driving the compensation lens in accordance with the hand-vibration, trembling of the image can be compensated.

Abstract: A wedge prism unit is positioned on the optical axes of the objective optical systems of two telescope systems of a binocular. The wedge prism unit includes a front wedge prism element and a rear wedge prism element that are oppositely oriented. When rotated by equal amounts in opposite directions, the wedge prism elements deflect incident light in a direction perpendicular to the rotation axis. The wedge prism unit is placed along the objective optical axes of the binocular, oriented to deflect the visual field to compensate for vibration. A control circuit controls a single motor according to a vibration sensor to deflect the visual field in a direction opposite to the vibration. The rotation axis is either within or outside of an imaginary plane containing both of the optical axes.

Abstract: A lens accessory attaching mechanism is provided to attach a lens accessory to a lens barrel. The lens attaching mechanism has four pairs of first and second rollers attached to the proximal end portion of the lens accessory into which the distal end of the lens barrel is inserted. The first and second rollers are equiangularly spaced in the circumferential direction of the lens accessory and are movable in a radial direction thereof. A ring spring arranged around all of the first and second rollers urges the rollers radially inwardly. An outer flange portion formed on the outer periphery of the lens barrel abuts the first and second rollers to restrict the movement of the lens accessory in the axial direction of the lens barrel.

Abstract: A slip clutch mechanism is provided with a clutch shaft rotated by a driving power source, a pair of slip pinions supported on the clutch shaft in such a manner as to be rotatable around the clutch shaft, and a pair of slip washers supported on the clutch shaft, in such a manner as to be rotatable as unified with the clutch shaft and movable in the axial direction of the clutch shaft and as to get into frictional contact with the individual sliding pinions at the inner sides thereof. A compression coil spring member is interposed between the slip washers and brings the slip washers into frictional contact with the slip pinions. An output shaft is rotated by one of the pair of slip pinions.

Abstract: A lens driving apparatus for moving a plurality of lens groups, in an optical axis direction, to change the spatial distance therebetween, including a supporting cylinder which is secured to an immovable portion of a lens barrel, a cam ring which is rotatably fitted on the supporting cylinder, at least two inner lens moving frames which are provided in the supporting cylinder so as to move in the optical axis direction, guide grooves which are formed on the supporting cylinder to guide the lens moving frames in the optical axis direction, cam grooves which are formed on the cam ring to move the lens moving frames along therewith, and cam followers which are secured to the inner lens moving frames and which extend through the corresponding guide grooves to be fitted into the corresponding cam grooves.

Abstract: A lens barrel is provided having a screw mount. The lens barrel includes a mount ring having a threaded portion, which can be engaged by a corresponding screw mount of the camera body to which the lens barrel is to be attached, a focus adjusting ring which is rotatably supported by the mount ring, a barrel body which is screw-engaged by the focus adjusting ring to support a focus adjusting lens, a linear movement guide member which is rotatably supported by the mount ring to restrict the movement of the barrel body so as to move only in the optical axis direction of the focus adjusting lens, and a frictional resisting member which resists the rotational movement of the linear movement guide member relative to the mount ring.

Abstract: A motor-driven zoom lens barrel including a zoom motor, a powered zooming mechanism which varies the focal length of a taking lens in accordance with the rotation of the zoom motor in the forward and reverse directions, a zoom operation ring which can be rotated, a rotational direction control circuit for rotating the zoom motor in the forward and reverse directions in accordance with the rotation of the zoom operation ring in the forward and reverse directions from a neutral position thereof, and a speed control circuit for controlling the rotational speed of the zoom motor in accordance with the angular displacement of the zoom operation ring from the neutral position.

Abstract: A zoom lens barrel having an adjusting ring connected to a cam ring through a gear ring. The cam ring is rotatably supported by a stationary cylinder in which some of the lens groups are housed. The gear ring is fixed to the cam ring. The stationary cylinder is provided with the adjusting ring, which is movable relative to the stationary cylinder and along the optical axis. The adjusting ring is connected to the cam ring in such a manner that the adjusting ring and the cam ring can be rotated relative to each other and can be moved along the optical axis as a single body.

Abstract: A process is provided for improving the resistance to deterioration when exposed to weather and the adherence to other materials of polypropylene, particularly in the form of moldings, which comprises subjecting a surface of polypropylene to the action of activated oxygen gas at a temperature below about 100.degree. C. in the presence of an N-alkyl or N-acyl 2,2,6,6-tetramethyl piperidyl compound for a time sufficient to improve such weather resistance and adherence.

Abstract: A process is provided for improving the resistance to deterioration when exposed to weather and the adherence to other materials of polypropylene, particularly in the form of moldings, which comprises subjecting a surface of polypropylene to the action of activated oxygen gas at a temperature below about 100.degree. C. in the presence of an N-alkyl or N-acyl 2,2,6,6-tetramethyl piperidyl compound for a time sufficient to improve such weather resistance and adherence.

Abstract: A lens barrel for a zoom lens in which zooming is achieved by moving both front and rear lenses but focussing is achieved by moving only the front lens. When a sliding ring slides linearly for zooming, a cam sleeve is rotated. A pin in the cam sleeve engages a cam groove in a moving frame for the front lens to thereby linearly move the front lens. Another cam groove in the cam sleeve engages a pin in the frame for the rear lens to thereby also linearly move it. Focussing is achieved by a threaded rotation of the frame for the front lens on the moving frame.

Abstract: A compact and lightweight zoom lens mount barrel in which the number of layers between the outer edges of lenses and the outer surface of the mount barrel is minimized and for which the assembly operation is simplified. A rear lens group moving cam slots is formed in a support sleeve and a fixed connecting sleeve is threadedly engaged with the support sleeve. Front and rear lens support frames are respectively engaged with the outer and inner periphery of the support sleeve. A front lens group moving cam slots is formed in the front lens group support frame. A fixed sleeve is engaged with the connecting sleeve by a stop screw.

Abstract: A two-lens group type zoom lens having a high magnification factor and simple structure yet having smooth transfer between normal zooming and macrophotographing positions. The positions of the first and second lens groups are defined by a respective zooming cam slot and lead slot formed in a cam sleeve. For focusing, a focusing operation sleeve is rotated to determine the position of the first lens group along the optical axis. A linear slot is provided extending from a telephoto end position of the zooming cam slot parallel to the optical axis direction of the lens. Additional circumferential slots may be provided extending from the zooming cam slot and lead slot and a click-stop mechanism utilized to stop the zooming operation sleeve at the telephoto end position and macrophotographing range position.

Abstract: An anti-yellowing additive is provided for environmentally acceptable stabilized vinyl chloride polymer compositions from which arsenic, beryllium, cadmium, lead, mercury, and thallium are substantially excluded, comprising at least one overbased sulfonate or phenolate compound of lithium, sodium, potassium, magnesium, calcium, strontium, barium, zinc, titanium, aluminum, zirconium, or tin, and a 1,3-diketone compound having 5 to 30 carbon atoms, which is a cyclic or open-chain 1,3-diketone or a lithium, sodium, potassium, magnesium, calcium, strontium, barium, zinc, aluminum, tin or zirconium salt thereof.

Abstract: An environmentally acceptable stabilizer composition is provided for enhancing the resistance to deterioration upon heating at 175.degree. C. of a vinyl chloride polymer from which lead, cadmium, mercury, thallium, and arsenic are substantially excluded, comprising (A) at least one zinc, alkali metal, or alkaline earth metal organic phosphate ester salt having per metal atom from one to a number equal to the valence of the metal of phosphate ester groups and from one to two organic groups per phosphate groups, the organic groups being alkyl, aryl, alkaryl, aralkyl, ether-interrupted allyl, or ether-interrupted aralkyl groups having from 1 to about 80 carbon atoms; and (B) at least one betadiketone compound having 5 to about 30 carbon atoms which is a cyclic or open-chain betadiketone or a zinc, alkali metal or alkaline earth metal salt thereof.A stabilized vinyl chloride polymer composition in which the environmentally acceptable composition is used as stabilizer is also provided.

Abstract: A stabilizer composition is disclosed that enhances the resistance to deterioration upon heating of vinyl chloride polymers. The stabilizer composition comprises (A) a metal salt of a sulfur-and nitrogen- free monocarboxylic acid or a phenol and (b) a metal salt of a phosphorous acid mono-ester in which the molar ratio of phosphorous acid mono-ester to metal is 1:1.Vinyl chloride polymer compositions stabilized with the above disclosed stabilizer composition are also disclosed.

Abstract: A stabilizer composition is disclosed that enhances the resistance to deterioration upon heating of vinyl chloride polymers. The stabilizer composition comprises (A) a metal salt of a sulfur--and nitrogen--free monocarboxylic acid or a phenol and (B) a metal P-hydrocarbonphosphonate having at least one to thirty carbon atoms in the hydrocarbon group.Vinyl chloride polymer compositions stabilized with the above disclosed stabilizer composition are also disclosed.

Abstract: An anti-yellowing additive is provided for environmentally acceptable stabilized vinyl chloride polymer compositions from which arsenic, cadmium, lead, mercury, and thallium are substantially excluded, comprising at least one basic inorganic compound of lithium, sodium, potassium, magnesium, calcium, strontium, barium, zinc, titanium, aluminum, zirconium, or tin, and a 1,3-diketone compound represented by the formula ##STR1## in which R is a hydrocarbon group having 1 to 18 carbon atoms, R' is a hydrogen atom, an acyl group ##STR2## or a hydrocarbon group having 1 to 18 carbon atoms, R' is a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, M is a hydrogen or one of the metals lithium, sodium, potassium, magnesium, calcium, strontium, barium, zinc, aluminum, and antimony, and n is the valence of the metal from 1 to 3.